Loading tanks of transport trucks is a hazardous and dangerous task. To prepare the tank for loading, it is necessary for a worker to open the hatch or hatches on the upper surface of the tank. The upper surface of the tank is typically cylindrical and often slippery causing frequent slips and falls by workers. Further, the worker must access the top surface again after the tank is loaded to close the hatch or hatches on the tank. Because of these hazardous conditions, it is known in the art to use safety cages to protect the workman, such as the one disclosed in U.S. Pat. No. 7,216,741.
Most safety cages in the art are ineffective in providing fall protection for transport trucks such as dry bulk transport trucks. The typical standard operating procedure for loading dry bulk transport trucks is to open the hatch at one location, drive the truck to a loading station for loading, and then close the hatch at the second location or return the truck to the original or another location suitable for closing the hatch. The hatch cover is normally hinged on a horizontal axis extending in the longitudinal direction of the tank and truck. When the hatch cover is opened, it is desirable to pivot the hatch cover to a fully open position in which the top of the cover rests on the upper part of one lateral side of the tank. If the side railing of a safety cage is spaced laterally outward a sufficient distance to permit the hatch cover to be fully opened, the side railing is positioned too far laterally to prevent the worker from falling. It also may be too far away to be used by the worker as a grab bar to regain balance or to stop a fall. Conversely, if the side railing of a safety cage is spaced laterally inward a sufficient distance to prevent the worker from falling, the hatch cover is not permitted to be fully opened.